2 Answers

2 votes

Yes. It affects some abilities and moves, such as attract. It also can effect evolution (like with burmy). Abiliites also can hinge on it, such as rivalry, which raises a pokemon's attack against one of the same gender.
Edit: No, I don't think it affects stats. Just IVs and EVs playing a role there, but I highlydoubt that IVs are determinded by gender.